Supporting structure for motors of vertical centrifugal pumps

ABSTRACT

A supporting structure for the transmissions and/or electric motors of vertical centrifugal pumps wherein the foundation is formed with a polygonal opening and carries support points each of which is recessed into the foundation midway between two corner portions of the opening. A metallic frame of polygonal outline consists of profiled frame members which support and extend tangentially of a ring-shaped flange for connection to the motor of a centrifugal pump. The corners of the frame rest on and are secured to the support points so that the frame is angularly offset relative to the surfaces flanking the opening in the foundation. This reduces the length and weight of the frame members as well as the magnitude of bending stresses. The natural frequency of the frame is higher than the exciter frequency when the motor which is carried by the supporting structure is in actual use.

United States Patent Bockau et a1.

SUPPORTING STRUCTURE FOR MOTORS OF VERTICAL CENTRIFUGAL PUMPS Inventors:Guenter Bockau, Varrel ll; Horst Schaefer, Rhade, both of Germany KleinSchanzlin & Becker Aktiengesellshaft, Frankenthal, Germany Filed: Mar.22, 1973 Appl. No.: 343,757

Assignee:

Foreign Application Priority Data Mar. 22, 1972 Germany; 2213852References Cited UNITED STATES PATENTS Eccles 248/19 Von Den Steinen248/17 X Pogue 248/20 Jolly 248/18 X Mar. 25, 1975 3,520,634 7/1970Bellati et a1... 415/219 R X 3,659,817 5/1972 Hendal 248/D1G. 1

Primary Examiner-J. Franklin Foss Attorney, Agent, or FirmMichael J.Striker [5 7] ABSTRACT A supporting structure for the transmissionsand/or electric motors of vertical centrifugal pumps wherein thefoundation is formed with a polygonal opening and carries support pointseach of which is recessed into the foundation midway between two cornerportions of the opening. A metallic frame of polygonal outline consistsof profiled frame members which support and extend tangentially of aring-shaped flange for connection to the motor of a centrifugal pump.The corners of the frame rest on and are secured to the support pointsso that the frame is angularly offset relative to the surfaces flankingthe opening in the foundation. This reduces the length and weight of theframe members as well as the magnitude of bending stresses. The naturalfrequency of the frame is higher than the exciter frequency when themotor which is carried by the supporting structure is in actual use.

9 Claims, 2 Drawing Figures SUPPORTING STRUCTURE FOR MOTORS OF VERTICALCENTRIFUGAL PUMPS BACKGROUND OF THE INVENTION The present inventionrelates to improvements in supporting structures for prime movers offluidoperated machines, especially vertical centrifugal pumps. Moreparticularly, the invention relates to improvements in supportingstructures for the transmissions and/or electric motors which serve todrive vertical centrifugal pumps.

SUMMARY OF THE INVENTION An object of the invention is to provide anovel and improved supporting structure for prime movers of hydraulicmachines, especially for transmissions and/or electric motors which areused to drive vertical centrifugal pumps for the circulation of coolant,clean water, waste water and/or other liquids.

Another object of the invention is to provide a sup porting structurewhose behavior in actual use can be calculated in advance with a highdegree of accuracy a polygonal opening and the support points are reandwhose natural frequency can be made so high that it invariably exceedsthe normal exciter frequencies.

A further object of the invention is to provide a supporting structureconsisting of a foundation and a metallic frame wherein the parts of theframe are subjected to negligible torsional stresses and to bendingstresses which are much lower than the bendingv stresses upon theframeparts of conventional supporting structures.

. An additional object of the invention is to provide a supportin gstructure wherein the static and dynamic forces are transmitted to thefoundation by way of bending moments and free of torsion.

Stillanother object of the invention is to provide a novel and improvedmounting of the frame on the foundation of a supporting structure forthe electric motors of vertical centrifugal pumps.

The invention is embodied in a supporting structure for prime movers ofhydraulic machines, especially for transmissions and/or electric motorsof vertical centrifugal pumps. The supporting structure comprises afoundation which may constitute the floor or roof of a plant, at leastthree spaced-apart support points provided on or in the foundation, apolygonal frame including a plurality of preferably profiled metallicframe members which are rigidly connected (preferably welded) to eachother at the corners of the frame, and a substantially annularmotorcarrier (preferably a ringshaped flange) which is supported by theframe so that the frame members are disposed substantially tangentiallyof the carrier. Each of the support points in or on the foundationserves as a rest for a different corner of the frame so that, when themotor which is supported by the carrier is in use, the static anddynamic forces to which the frame members are subjected are transcessedinto the foundation in such a way that each thereof is locatedintermediate (preferably exactly midway) between two corner portions ofthe opening. Thus, if the opening and the frame have a square outline,the frame can be angularly offset by relative to the opening. I

The novel features which are considered as characteristic of theinvention are set forth in particular in the appended claims. Theimproved supporting structure itself, however, both as to itsconstruction and its mode of operation, together with additionalfeatures and ad vantages thereof, will be best understood upon perusalof the following detailed description of certain specific embodimentswith reference to the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a plan view of a supportingstructure which embodies the invention; and

FIG. 2 is a vertical sectional view as seen in the direction of arrowsfrom the line A-B of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The supporting structure whichis best shown in FIGS. 1 and 2 comprises a foundation 5 having apolygonal opening 4, here shown as a square opening 4. The foundation 5is provided with four built-in or recessed support points 6' each ofwhich is adjacent to the opening 4 and is located intermediate,preferably exactly midway, between two neighboring corner portions ofthe opening.

The supporting structure further comprises a metallic frame I which isalso of polygonal outline and is shown in the form of a square includingfour welded-together profiled metallic frame members 2 which extendtangentially of and support a round carrier or flange 3 for thetransmission and/or electric motor (not shown) which drives a verticalcentrifugal pump, not shown. The foundation 5 may constitute the flooror the roof of a shop where the centrifugal pump is mounted to circulateliquid coolant, fresh water or waste water.

The frame members 2 meet at the four corners 6 of the frame 1 and eachof the four corners 6 is supported by and is secured to one of thesupport points 6' in the foundation 5. Due to the fact that the profiledframe members 2 extend tangentially or substantially tangentially of theflange 3, the weight of the parts which are secured to the flange 3 andthe exciting forces which develop when the centrifugal pump is in useproduce stresses which are transmitted to the frame 1 in such a way thatthe frame is not subjected to any torsional stresses and only tomoderate bending stresses. It will be noted that the members 2 of theframe 1 form a square which is angularly offset by 90 relative to theside surfaces of the foundation which surround the opening 4. In manypresently known supporting structures for vertical centrifugal pumps,the frame members of the frame are parallel to the surfaces bounding theopening in the foundation. An advantage of the improved supportingstructure is that the length of the frame members 2 can be reduced toapproximately 70 percent of the length of frame members in conventionalsupporting structures. The weight of the bending moment upon the framemembers is also reduced to 70 percent. The extent of flexing in thecentral portions of frame members 2 is reduced to 35 percent of theextent of flexing of frame members in conventional supportingstructures. This results in a rise of natural frequency to about l70percent of natural frequency of conventional supporting structures.

It has been found that the improved supporting structure provides asuperior, safer and vibration-free carriage for the transmissions and/orelectric motors of centrifugal pumps. All static and dynamic forces aretransmitted directly to the frame 1 with accurately determinable bendingmoments and free of torsion. The savings in material are substantialeven though the weight of the frame is less and its rigidity is higherthan that of frames in conventional supporting structures.

If desired, the frame can be provided at little additional cost withreinforcing or stiffening means (not shown) to further increase thenatural frequency.

Without further analysis, the foregoing'will so fully reveal the gist ofthe present invention that others can, by applying current knowledge,readily adapt it for various applications without omitting featureswhich fairly constitute essential characteristics of the generic orspecific aspects of our contribution to the art and, therefore, suchadaptations should and are intended to be comprehended within themeaning and range of equivalence of the claims.

What is claimed as new and desired to be protected by Letters Patent isset forth in the appended claims:

'1. A supporting structure for prime movers of hydraulic machines,especially for transmissions and/or electric motors of verticalcentrifugal pumps, comprising a foundation; atleast three spaced apartsupport points provided on said foundation; a polygonal frame includinga plurality of metallic frame members, each of said frame members beingsecured at one end to one of said support points and at the other end toanother of said frame members spaced from the end of the latter which issecured to another corresponding support point; and a substantiallyannular motor carrier sup ported by said frame, said frame members beingsubstantially tangential to said carrier and the static and dynamicforces to which said frame members are subjected being transmitted tosaid foundation directly by way of bending moments and free of torsion.

2. A supporting structure as defined in claim I, wherein said frame hasa substantially rectangular outline and the number of said supportpoints is'four so that each of said support points serves as a rest fora different corner of said frame.

3. A supporting structure as defined in claim 2, wherein said frame hasa substantially square outline.

4. A supporting structure as defined in claim 1, wherein said framemembers are profiled.

5. A supporting structure as defined in claim 1, wherein said foundationhas an opening of polygonal outline having a plurality of cornerportions, each of said support points being recessed into saidfoundation intermediate two corner portions of said opening.

6. A supporting structure as defined in claim 5, wherein said openingand said frame have square outlines and said frame is angularly offsetby relative to said opening.

7. A supporting structure as defined in claim 1, wherein said carrier isa ring-shaped flange which is connected to each of said frame members.

8. A supporting structure as defined in claim 1, wherein the number ofsupport points exceeds three.

9. A supporting structure as defined in claim 1, wherein said foundationhas an opening of rectangular outline and a plurality of cornerportions, each of said support points being located intermediate saidcorner portions, and each of said frame members being angu-

1. A supporting structure for prime movers of hydraulic machines, especially for transmissions and/or electric motors of vertical centrifugal pumps, comprising a foundation; at least three spaced apart support points provided on said foundation; a polygonal frame including a plurality of metallic frame members, each of said frame members being secured at one end to one of said support points and at the other end to another of said frame members spaced from the end of the latter which is secured to another corresponding support point; and a substantially annular motor carrier supported by said frame, said frame members being substantially tangential to said carrier and the static and dynamic forces to which said frame members are subjected being transmitted to said foundation directly by way of bending moments and free of torsion.
 2. A supporting structure as defined in claim 1, wherein said frame has a substantially rectangular outline and the number of said support points is four so that each of said support points serves as a rest for a different corner of said frame.
 3. A supporting structure as defined in claim 2, wherein said frame has a substantially square outline.
 4. A supporting structure as defined in claim 1, wherein said frame members are profiled.
 5. A supporting structure as defined in claim 1, wherein said foundation has an opening of polygonal outline having a plurality of corner portions, each of said support points being recessed into said foundation intermediate two corner portions of said opening.
 6. A supporting structure as defined in claim 5, wherein said opening and said frame have square outlines and said frame is angularly offset by 90* relative to said opening.
 7. A supporting structure as defined in claim 1, wherein said carrier is a ring-shaped flange which is connected to each of said frame members.
 8. A supporting structure as defined in claim 1, wherein the number of support points exceedS three.
 9. A supporting structure as defined in claim 1, wherein said foundation has an opening of rectangular outline and a plurality of corner portions, each of said support points being located intermediate said corner portions, and each of said frame members being angularly offset relative to said opening in said foundation. 